[Message posted by Humberto Barreto for Richard McKenzie.] John Maurice Clark is widely quoted as saying (or having written), "An irrational passion for dispassionate rationality will take the joy out of life." The quote is often abbreviated, with the "will take the joy out of life" being left off and with the first part said to define an economist. I've spent a good deal of time trying to track down the source, going through pages of Internet hits, but I've never seen the source given. Would someone on this list give me the source or, perhaps, some direction on my search. I'm trying to track down the source because I am working on a book on the evolution of rationality in economics, with some attention to how modern neuroscience/biology can speak to the limits of rationality. Thanks in advance. Richard McKenzie